"People announce new relationships on Facebook," said Liz, 19, of Ontario, Canada. "I find out about my friends new boyfriends on Facebook before I even hear it from them."

The problems with social networking sites go beyond a loss of privacy; they can also exacerbate trust issues in romantic relationships, specifically in the form of Facebook wall posts or MySpace comments. "I don't trust the girls that post on my boyfriend's wall," said Liz. "I wish I would see wall-to-wall comments between my boyfriend and these girls. I trust my boyfriend, but I'm curious what he's saying back to them."

More problems can arise thanks to Facebook messages. Tamar, 16, of Silver Springs, M.D., accidentally logged into her boyfriend's Facebook account because the username and password had automatically saved. Thinking it was her account, she clicked to check the new messages. When she saw messages from people she didn't know, she realized her error. But one message caught her eye, it was from a girl asking, "Who is Tamar?" Her boyfriend's response was "Tamar is my annoying girlfriend who will be gotten rid of shortly." This message was dated three weeks before Tamar saw it. When she confronted him, he tried to deny it, but the messages were there as clear evidence.

Andrea, 19, of Orlando, Florida, found out about her (now ex) boyfriend's summer fling with his family friend through Facebook messages. The two had been sending flirty messages back and forth, and after she saw them, she dumped him.

But Facebook isn't all bad. Liz actually met her boyfriend thanks to Facebook. They attended the same party and noticed each other, but didn't get a chance to talk. A few days later, he was looking through the pictures from the party and saw a picture of Liz. She was tagged on the photo, so he checked out her profile, saw they had a ton of common interests, and messaged her. They've been together for nearly a year now.

Many have expressed concerns about future employers checking their Facebook accounts before even interviewing them. At her internship, Elena, 20, of New York, N.Y., said that her boss asked her to print out the profiles of any potential employees of whose accounts she was able to gain access. "I was shocked to discover that they actually do check your profiles," said Elena. "I cleaned up my profile immediately." You may think you're safe if your account is set on private, but as Nina, 17, of Providence, R.I. discovered, there are ways around the privacy settings. "Facebook has an intense security system, but it's easy to bypass a lot of it if you just look closely and worm your way around," said Nina. "I'm not a hacker by any means, but I have managed to get access to a lot of things that I shouldn't be able to access." This means that she's discovered a way to look at private profiles. And if she has discovered it, you can bet on the fact that many others have discovered this as well.

- Kristen O'Gorman, Associate Editor